From Latinsalvo, ablative of salvus, the past participle of salvāre (“to save, to reserve”), either from salvo jure literally 'the right being reserved', or from salvo errore et omissone 'reserving error and omission'.

A 1719 alteration of salva (1591) "simultaneous discharge of guns," from Latinsalva (“salute, volley”) (compare salve, also from Italian), from Latinsalve (“hail”), imperative of salvere: "be in good health!," the usual Roman greeting, regarded as imperative of salvere "to be in good health,"